This invention relates to cephalosporin antibiotic compounds and intermediates in the synthesis thereof. In particular, it relates to cephalosporin compounds substituted in the 7-position with a 2-(2-aminooxazol-4-yl)-2-(substituted-oximino)acetamido group and in the 3-position with a variety of substituents, such as fluoro, chloro, bromo, hydroxy, acyloxymethyl, carbamoylmethyl, substituted and unsubstituted methyl pyridinium groups and heterocyclic thiomethyl groups containing 5- and 6-membered heterocyclic rings.
In recent years, much research has been done in the area of cephalosporins containing a 7-[2-(2-aminothiazol-4-yl]-2-(substituted oximino)acetamido side chain, with a wide variety of substituents in the 3-position of the cephalosporin. Two of the most notable examples of such compounds are the potent antibiotics (a) sodium 7-[2-(2-aminothiazol-4-yl)-2-methoximinoacetamido]-3-acetoxy-3-cephem-4-ca rboxylate disclosed by Heymes, et al. in U.S. Pat. No. 4,152,432 and (b) the compound of the formula ##STR1## disclosed by O'Callahan et al. in U.S. Pat. No. 4,258,041.
The cephalosporin antibiotics of the instant invention possess excellent antibiotic activity while differing in structure from the aforementioned compounds and other compounds previously disclosed.